The government must ensure that every UK airport employs drone protection systems.

The demand came from airline pilots after flights departing Heathrow were temporarily grounded yesterday evening after reports of a drone sighting at the airport.

The Met Police were called to UK’s busiest airport, which serves more than 200,000 passengers a day, to investigate.

A Ministry of Defence spokesman said: “We are deploying specialist equipment to Heathrow Airport at the request of the Metropolitan Police.”

Take offs resumed after an hour of disruption but left a long backlog of flights.

The London hub tweeted shortly before 6pm: “We are responding to a drone sighting at Heathrow and are working closely with the Met Police to prevent any threat to operational safety.

“As a precautionary measure, we have stopped departures while we investigate. We apologise to passengers for any inconvenience this may cause.”

The northern runway was closed as investigations were carried out.

It comes just weeks after flights from Gatwick were brought to a standstill when drones were sighted at the UK’s second busiest airport before Christmas – affecting more than 140,000 passengers and 1,000 flights.

The Department for Transport had announced plans to increase drone restrictions around airports just 24 hours earlier.

British Airline Pilots’ Association general secretary Brian Strutton said: “This second drone incident in less than a month has shown how important it is that airports invest in drone protection technology immediately.

“The government should ensure that every airport does so in the interests of public safety and should accelerate and strengthen its other drone legislation planned for later this year. It’s time to act swiftly and decisively.

“An aircraft or helicopter collision with a drone has the potential to be catastrophic and so it’s right that Heathrow shut until it was sure flights could take off and land safely again.

“While it may be frustrating for the passengers who are delayed, it’s their safety that must come first.”

Aviation minister Liz Sugg is due to host a meeting with UK airport bosses tomorrow to discuss their resilience against drone attacks.

Transport secretary Chris Grayling told MPs prior to the Heathrow incident that the Ministry of Defence remains on standby to deal with any further problems at Gatwick or any other airport if required.

“There is no question that lessons have to be learned from what happened at Gatwick,” he said.

“Passengers have to be able to travel without fear of their trips being disrupted by malicious drone use.

“Airports must be prepared to deal with incidents of this type, and the police need the proper powers to deal with drone offences.

“We must also be ready to harness the opportunities and benefits that the safe use of drones can bring.”